The present invention relates to a clip-holder instrument for "clipping" blood vessels, and especially to a new surgical tool particularly adequate to place clips, of alpha configuration ending in "V", on brain blood vessels.
The clip-holder pliers used at present have several drawbacks that in view of the particular and delicate task for which they are used, such as in neurosurgery, make the surgeon's task especially difficult when he requires the best working conditions and, more importantly, have an operating field of vision free from obstacles.
In the above mentioned pliers the clip is closed. This means that, when the pliers are open the clip is closed, to open it and place it in position, the pliers must be closed, the force to be applied varying according to the type of pliers used. Some of them (such as those known as the Mayfield and Scoville pliers), when they are closed for the clip to open, are unsafe and the clip may fall out or change its position. In the pliers called Yassagil the mechanism is similar with the added disadvantage that it is difficult to unfasten the clip from the pliers when it is placed.
The Olivecrona clip-holder pliers, at present obsolete, carried the clip open. The drawback in such a configuration consisted in the fact that the fastening of the clip in its position on the blood vessel was obtained by the strength of the surgeon's hand and not through the elasticity of the clip. As a consequence of the foregoing, deficient fastening of the clip on the blood vessel could occur or, alternatively, excessive pressure could be created that, in the case of carelessness, could section the aneurysmatic neck.
Another important disadvantage of the above mentioned pliers is that they obstruct the surgeon's field of vision, as the jaws of the pliers are larger than the clip to be placed. It must be borne in mind that the surgeon works within the encephalic mass, with a microscope. It sometimes happens that it is not possible to verify if the clip is correctly placed until it is released. If it is not in the correct position, which frequently happens, the clip must be withdrawn and replaced in the correct position.
Another disadvantage of the above mentioned pliers is that it is difficult to withdraw a clip that has been incorrectly placed, added to the fact that it is not possible to turn it in the pliers when the operation so requires. This obliges the surgeon to turn his hand according to the position of the clip, which is complicated by the above mentioned drawback that the pliers obstruct the surgeon's field of vision for placing the clip.
The present instrument of the invention eliminates all these disadvantages and constitutes a very practical and efficient tool.
One of the prinicpal advantages of the present invention is that it provides an instrument that enables the surgeon to have a free field of vision all the time of the area and the blood vessel to be "clipped" as well as the clip carried by the instrument.
Another advantage is that, in an inoperative position the instrument carries the clip open, but it can also be carried in a closed position by means of a slight pressure of the surgeon's hand. In a preferred embodiment of the present invention, the clip is carried within a tube, therefore the possibility that the clip may fall out of the tube or modify its position is eliminated.
Further advantages are that the clip can be carried in the instrument and that its rotation can be controlled with the same hand that holds it, thus sparing the operator from having to turn his hand in order to rotate the clip.
It is also very important to point out that the clip is easily unfastened from the instrument and that it can also be withdrawn without any difficulty. Although the instrument requires pressure to release the clip, the clip closes on the blood vessel due to its own elasticity, and the pressure of the hand is exercised on a lever that is similar to the trigger of a firearm and is easily operated. The instrument forms a grip handle that provides ample safety.
Other advantages and characteristics of the invention may be observed in the course of the description of the preferred embodiment of the present invention.